Xilinx, Inc.

David Nguyen Van Mau

Yassine Rjimati

Tetse Jang

Amit Singh

Vi Chi Chan

Kevin Chung

Taneem Ahmed

Mehrdad Parsa

A computer-implemented method of implementing a circuit design that includes an initial network within a programmable logic device can include generating a first choice network from the circuit design according to a first synthesis technique and determining a placement for the first choice network. At least a second choice network can be generated from the first choice network according to a second synthesis technique. A placement for the second choice network can be determined. The placement for the first choice network can be compared with the placement for the second choice network. A placement and corresponding choice network can be selected according to the comparison, and output.

Implementation flow for electronic circuit designs using choice networks

Method and apparatus for mapping flip-flop logic onto shift register logic is described. In one example, a method of processing flip-flop logic in a circuit design for implementation in an integrated circuit is provided. A chain of flip-flops in the circuit design is identified. The chain of flip-flops includes first and second control signals. A shift register is instantiated in a logical description of the circuit design for the chain of flip-flops. A shift register is instantiated in the logical description for the chain of flip-flops. First and second control chains of flip-flops are instantiated in the logical description for the first and second control signals, respectively. A multiplexer is instantiated in the logical description and is configured to select among an output of the shift register, an asserted logic state, and a de-asserted logic state based on outputs of the first and second control chains.

Method and apparatus for mapping flip-flop logic onto shift register logic

A method is provided to automatically allocate resources of an integrated circuit (IC) to form multipliers in a given design to optimize the use of IC resources. Information about the multipliers in the design is extracted to place the multipliers into a priority order. The priority allows primitives in the IC, like DSP blocks LUTs or MUXCYs to be economically allocated to the multipliers. The ordering criteria can include: (1) a user defined criteria, (2) the number of primitives required to implement a multiplier, or (3) a size of the multiplier operands. This invention further optimally allocates LUTs and MUXCYs when DSP48 blocks are exhausted. The steps for generating a multiplier include: constructing a partial product matrix and minimizing the adders used in the multiplier by minimizing the size of support for the partial products. Either LUTs or MUXCYs are selected depending on the size of support determined.

Resource and context based multiplier generation

Systems, methods, software, and techniques implementing a multiplexer mapper tool can be used to construct a binary decision diagram (BDD) or related structure representing a series of dependent multiplexers. Once in this form, the BDD can be manipulated in a variety of ways including reordering of nodes according to multiplexer selector and minimizing the BDD using conventional techniques. Once properly processed, the BDD can be further separated into smaller BDDs and mapped to existing cell library design elements.

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Seyssinet, France

David Nguyen Van Mau